In an electronic device of the known art such as a smartphone, a cover made of a clear glass plate or a clear acrylic plate and covering a display unit is bonded to a cabinet using a piece of double-sided tape having a frame shape.
The recent increase in the display screen sizes has involved a further reduction of the width of regions to which the double-sided tape adheres, which has made it difficult to ensure a sufficient bonding strength by using the double-sided tape.
To address this problem, it is conceivable to use a photo-curable adhesive, for example. Such a photo-curable adhesive provides high production efficiency since it remains uncured when it is not irradiated with UV or visible light, and is cured by short-time irradiation with UV or visible light. Unfortunately, since a peripheral edge portion of the cover which covers a display unit is provided with black printing to improve the appearance, UV or visible light cannot reach the backside of the black printing.
In view of this, for example, Patent Document 1 describes a method of indirect bonding with the use of a photo-curable adhesive. According to this method, adhesion surfaces to which the photo-curable adhesive is applied are configured as reflection surfaces which reflect light. In this manner, gaps between the reflection surfaces are irradiated with UV or visible light.